Piezoionic sensors based on formulated PEDOT:PSS and Aquivion ® for ionic polymer–polymer composites

Abstract In this work, an ionic polymer–polymer composites (IP 2 Cs) was developed as piezoionic sensors based on Aquivion ® perfluorinated conducting membranes and modified PEDOT:PSS electrodes. The influence of solvent annealing, additive concentration and its nature (ionic liquid (IL), Aquivion ® ,…) on the electronic conductivity and the mechanical properties of modified PEDOT:PSS electrodes is investigated. The design of flexible free-standing PEDOT:PSS electrodes provides a new way of IP 2 Cs conception. Tri-layers are elaborated either by drop-casting or by thermocompressing of electrodes on top of commercial Aquivion ® membranes swelled by an IL 1-ethyl-3-methylimidazolium bis (trifluoromethyl-sulfonyl) imide. The open-circuit voltage output is measured during bending stimulation experiments as function of the mechanical perturbation amplitude. These IP 2 Cs made from Aquivion ® behaves as soft mechanical strain sensors with large electrical output signal as high as Δ E = 2.9 mV (Δ ϵ = ±2%) under optimal conditions. The influence of the IP 2 C’s manufacturing process, grade of Aquivion ® membrane, and electrode’s properties is investigated. This study emphasized the significant contribution of the electrode’s mechanical properties that appears as a critical parameter for the development of high performance piezoionic sensors. In the near future, we will explore the opportunity to employ these Aquivion ® -based IP 2 Cs as soft strain sensors for robotic and medical applications.